Mechanistic Studies for Synthesis of Bis(indolyl)methanes: Pd-Catalyzed C–H Activation of Indole–Carboxylic Acids with Benzyl Alcohols in Water

FeCl3·6H2O as a Mild Catalyst for Nucleophilic Substitution of Symmetrical Bis(indoyl)methanes

In this paper, unsymmetrical bis(indolyl)methane (BIM) and 3-alkylindole derivatives are smoothly synthesized from symmetrical BIMs with a variety of nucleophiles including heteroaromatic/aromatic compounds, allylsilane and alkynylsilane. FeCl₃·6H₂O is found to be a mild and highly effective catalyst for this nucleophilic substitution reaction in which N-methyl-2-phenylindole behaves as a good leaving group in the C_sp³-C_sp² bond cleavage reaction. The operational ease, nonexpensive and environmentally friendly catalyst, mild reaction conditions, broad functional group tolerance, and scalability of this reaction strategy are advantages of the present procedure.

Direct Substitution of Alcohols in Pure Water by Brønsted Acid Catalysis

With the increasing concern for sustainability, the use of environmentally friendly media to perform chemical processes has attracted the attention of many research groups. Among them, the use of water, as the unique solvent for reactions, is currently an active area of research. One process of particular interest is the direct nucleophilic substitution of an alcohol avoiding its preliminary transformation into a good leaving group, since one of the by-products in this approach would be water. The direct substitution of allylic, benzylic, and tertiary alcohols has been achieved through S_N1-type reactions with catalytic amounts of Brønsted or Lewis acids; however, organic solvents are often required. In this review, the pioneering S_N1 approaches performed in pure water and in the absence of a metal based Lewis acid are compiled and discussed.

Direct substitution of benzylic alcohols with electron-deficient benzenethiols via π-benzylpalladium(ii) in water

An efficient and environmentally benign method for the direct nucleophilic substitution of benzylic alcohols with electron-deficient benzenethiols in water is developed. This strategy is an attractive atom-economical process, which affords the desired products along with water as the sole co-product.

Facile synthesis of bis(indolyl)methanes catalyzed by α-chymotrypsin

A mild and efficient method catalyzed by α-chymotrypsin was developed for the synthesis of bis(indolyl)methanes through a cascade process between indole and aromatic aldehydes. In the ethanol aqueous solution, a green medium, a wide range of aromatic aldehydes could react with indole to afford the desired products with moderate to good yields (from 68% to 95%) using a little α-chymotrypsin as catalyst.

Synthetic methodologies of achiral diarylmethanols, diaryl and triarylmethanes (TRAMs) and medicinal properties of diaryl and triarylmethanes-an overview

This review covers the synthesis of achiral diarylmethanols, diaryl and triarylmethanes and the bioactivities of diaryl and triarylmethanes during 1995 to 2013.

Mercaptobenzoic acid-palladium(0) complexes as active catalysts for S-benzylation with benzylic alcohols via (η3-benzyl)palladium(ii) cations in water

Mercaptobenzoic acid-palladium(0) complexes show high catalytic activity for S-benzylation with benzylic alcohols via the (η³-benzyl)palladium(ii) cation in water. The catalytic system can be performed using only 2.5 mol% Pd₂(dba)₃ without the phosphine ligand or other additives.